Let X 1, X 2, ⋯ be independent identically distributed random variables having a common probability density function f. After a so-called kernel class of estimates f n of f based on X 1, ⋯, X n was ...

Leonard Fortuin, Five Popular Probability Density Functions: A Comparison in the Field of Stock-Control Models, The Journal of the Operational Research Society, Vol. 31, No. 10 (Oct., 1980), pp.